I installed an add-on but can't get it to appear on the add-on toolbar. Customise does not offer the add-on.

The add-on is the ad blocker. It is actually used in the demonstration of how the add-on toolbar works but I simply can't get it to appear there.
I have re-started.
Tried right click & customise.
Disabled then re-enabled add-ons.

How do I make it available for use?

The add-on is the ad blocker. It is actually used in the demonstration of how the add-on toolbar works but I simply can't get it to appear there.
I have re-started.
Tried right click & customise.
Disabled then re-enabled add-ons.
How do I make it available for use?